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Tempus Fugit

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“Remember, Mr. Allen,” Dr. Stein says, “assuming you achieve the proper velocity and open the wormhole, you will only have 1 minute and 52 seconds to save your mother and return.”

“I know,” Barry says.

“Or else – ”

“I know,” Barry repeats.

“Clear the path!” Cisco’s voice calls, audible to both Stein and Barry over the intercom. There’s nary a hint of static. Testament to the engineering know-how of STAR Labs. Reassuring, in this moment, even despite its source.

Everything STAR Labs has ever done – every breakthrough, every new idea, every advance in the field of science – it all shares the same source. The man who had called himself Dr. Harrison Wells. Or, as Barry now knows him, Eobard Thawne. The man who had killed his mother.

Barry could comfort himself by thinking that the intercom had probably been built by subcontractors. That clear sound transmission over a distance is a well-understood problem with well-understood solutions, requiring no future technology in order to function. That there may be no trace of the man who had called himself Harrison Wells in their theory or construction.

Given that Barry is about to risk everything – push himself farther, stretch himself thinner, jeopardize the fabric of time and space itself – on the strength of Thawne’s intellect – it’s more comforting to think that static-free communication is some kind of portent of success.

“You hold both our futures in your hands now, Mr. Allen.” Stein sighs, briefly regretful. Then his expression firms into one of determination. “And I know you can do it.”

Stein holds out his hand. Barry accepts it, briefly.

“Come on, Stein, clear the path!” Cisco sounds impatient; Stein bristles, but Barry shakes his head. He can hear Cisco’s worry and panic underneath his irritation. And it’s not all because, if Stein is still standing inside the particle accelerator when it comes online, he’ll be dust.

Cisco may be the one person who is taking the news of Harrison Wells’ betrayal less well than Barry. And that’s quite the bar to clear.

“Go on, Doctor,” Barry tells Stein, pushing the mess currently passing for his emotions back into their box. “Get back to the control room. You can monitor me from there.”

“Good luck,” Stein says, and retreats.

Then Barry is alone. Alone, standing in the heart of the particle accelerator. Alone, waiting to start the run that will take him into the past. Alone, for the first time since he’d learned –

Since he’d learned –

I stabbed your mother in the heart –

“Shut up,” Barry says out loud.

“I didn’t say anything,” Eobard Thawne replies.

Barry nearly jumps out of his skin. He spins in a circle, fast, fast, thinking – Thawne is supposed to be upstairs, on the roof, in his timeship, waiting for the moment Barry opens the wormhole. If he’s not there – what else is part of his plan, what else has Barry missed, how has Thawne betrayed them this time –

There’s nothing. Barry is alone, and even the intercom is quiet.

“Okay,” Barry says to himself. “Okay, get a grip.”

No one replies. Barry can’t decide if that’s a good sign or not. Either the stress is making him crazy, or –

Or nothing. Thawne is on the roof, waiting for the fulfillment of all his nefarious plans. Barry is in the heart of the particle accelerator. The thrum of machinery around him is comforting, familiar. This is STAR Labs in its purest form. Free from the malice of its creator, the technology continues on, unknowing and uncaring of the drama about to be played out in its heart.

Barry envies it.

On the floor in front of him, two strips of marking tape cross to form an X. That X represents a carefully calculated distance from the particle Stein and Thawne will be generating. So that when Cisco calls the time, when Barry starts running, pushing his hardest from the very beginning, Barry will be traveling at the right velocity when he reaches his destination. So that he collides with the particle at speed, and their reaction generates enough power to breach the space-time barrier and open the wormhole that is the key to all of their plans.

One point twenty-one gigawatts, Barry thinks with an edge of hysteria, and wonders why no one has made a Back to the Future joke yet.

“Getting close,” Cisco says over the intercom. “Doing okay, Barry?”

“Fine,” Barry says. It comes out just that far side of high-pitched that gives away the lie.

“Not much longer,” Cisco says. Caitlin’s voice can be heard in the background, murmuring something indistinct. “We’re starting the countdown now.” There’s a moment of silence, then Cisco comes back on the line. Adds, “Just breathe.”

It’s good advice. Barry takes it. He focuses on the air moving in and out of his lungs. Around him, there’s a deepening rumble as the particle accelerator begins to come online. It’s not dangerous yet to be standing where Barry is standing, but it will be, soon. He’ll have to start moving before then.

The thought makes Barry tense. He forces himself to relax. He runs best when he’s calm. Limber. When he’s one with the speed force.

He relaxes, and as he does, time slows down around him.

“You’re becoming reliant on your powers,” Eobard Thawne says. “That’s good, Barry. That means you’re gaining strength.”

Barry jumps again.

“No, no, don’t tense up,” Thawne scolds. “When you do, you lose your connection to the speed force. And there’s still a few more things I need to tell you before you take your – ” A pause; a chuckle. “Your ‘leap of faith’.”

“You’re talking to me through the speed force,” Barry gasps, sick realization spreading through him. He has no proof of that, only his intuition, but his intuition has saved him before. He’s learned to rely on it.

“Quite correct,” Thawne agrees. He’s nowhere to be seen – Barry is still alone, in body – but his voice is as clear in Barry’s ear as if they were side by side.

“How?” Barry can’t help asking.

There’s a thoughtful humming sound, and Barry’s mind’s eye presents him with a perfect mental image, unbidden: Dr. Wells in his wheelchair, fingers steepled thoughtfully under his chin, eyes glinting with suppressed excitement over his glasses. Excitement, and not a little mischief, that quirk that had always made Barry feel as if Wells were sharing a private joke just with him.

The burgeoning half-smile on Barry’s face drops away. They’d had something private in common, all right. But it hadn’t been a joke, and it hadn’t been something they’d shared. It had been something that only Wells – only Thawne – had known about. And if there had been genuine amusement in Wells’ eyes, if it hadn’t all been part of his front, then it had come from Wells’ enjoyment of his superior position.

His knowledge. Knowledge is power, after all. A motto so central to the man who had posed as Harrison Wells that he’d had it engraved over the door to the particle accelerator. If Barry looks up, he’d see it now.

Barry keeps his gaze on the floor. It doesn’t stop him from hearing, though, when Eobard Thawne stops humming thoughtfully and actually answers Barry’s question.

“The speed force is something all speedsters share,” Thawne says. “It’s not a separate capability that each of us has. It really is like the movies say.”

“It has a light side and a dark side and it holds the world together?” Barry quips, reaching for sarcasm as an instinctive defense.

It’s no defense at all, not really, not when Thawne speaks again in Wells’ voice, that voice that Barry has depended on, that he still knows so well that he can hear the smile that must be on Wells’ face when he answers. “It holds us all together,” is what Wells says. “All speedsters share a connection to the same speed force.”

“And we can speak through it.”

“The speed force transcends space. That’s the first thing you need to know, Barry. There is no difference between the speed force where you are and the speed force where I am. There is no difference between the speed force here, in STAR Labs, and the speed force on Alpha Centauri.”

Alpha – “Have you been to Alpha Centauri?” Barry asks – eagerly, too eagerly. Betraying interest. Forgetting for a moment that he’s not talking to Dr. Harrison Wells, longtime icon, but instead to Eobard Thawne, villain. Murderer.

But it’s hard when Thawne chides, “Focus, Barry,” and it’s just like any other moment before a big effort, the quiet before the storm. Wells’ voice in Barry’s ear has always been his touchstone. His center.

And maybe it makes Barry weak, that he pushes away his newfound knowledge for a moment. Forgets Wells’ duplicity, forgets his mother’s death, forgets everything, and just listens. Takes that calm certainty into himself and makes it his.

Maybe it makes Barry weak. Or maybe it just makes Barry pragmatic. He’s got to do this, and he’d be a fool to turn down any advantage he can get.

So Barry breathes, and focuses, and asks, “All right. The speed force transcends space. Why do I need to know that?”

“When you break the space-time barrier, you’ll be completely contained within the speed force. You will exist outside of space. And when you leave the speed force – ”

“I can reappear in any point in space I choose,” Barry completes. “So long as I have the speed to reach it. Which is what the particle is going to give me.”

The smile is back in Wells’ voice. This time it’s proud. “That’s right.”

“And the second thing you want to tell me is that the same thing applies to time,” Barry guesses. “That I can leave in any point in time I want, as long as I have the speed. That’s how I’ll travel back to the night – ”

He cuts himself off, but the thought completes in his head. The night of my mother’s death.

Just like that, Barry’s bubble of denial pops. The man speaking to him through the speed force isn’t Wells. It isn’t the man who’d helped Barry, mentored him, nurtured him. Whose good opinion Barry had courted, whose pride in Barry had been Barry’s joy, whose faith in Barry had been the foundation for Barry’s own belief that he could be a hero.

Why help me save so many people?

Because I needed you to get fast. Fast enough to rupture the space-time barrier and create a stable wormhole through which I could return home.

Forgetfulness, it turns out, will only get Barry so far.

“You’re absolutely right,” Thawne is saying. “When you’re in the speed force, you’ll have access to all of time and space at once. The only restrictions are your speed and your focus. Speed isn’t going to be a problem. Not like last time you traveled through time.”

The last time Barry had traveled through time, he’d only gone back twenty-four hours. He hadn’t had the speed to go farther. That, too, had been part of the reason why Thawne had always been pushing Barry to go faster.

“This time you’ll have the extra boost from the hydrogen particle. Which means that all you need is focus.”


“Yes, Barry. Focus. To guide your steps. You’ll need to focus on where you want to go.”

Barry knows what Thawne is going to say next. He still hopes, futilely, that he’s wrong.

“So think about that night,” Thawne says. His voice has gotten quiet. Intimate. “Think about your mother.”

No, Barry wants to say. He shudders all over with the revulsion of it, hearing Thawne’s voice turn reminiscent, recounting the worst night of Barry’s life.

Maybe the second worst, now. That night had been terrible. But it had been straightforward. The good guys, the bad guys – the victory and the tragedy – it had changed Barry, shaped the man he’d become, but it hadn’t changed his past. His memories of his mother still live within him. Give him strength.

Now Barry knows betrayal. Now Barry knows it’s possible to ruin more than just the future. It’s possible for someone to reach back into Barry’s memories and taint them, turning them from a source of strength to a source of pain.

Think about your mother –

Yellow streaks and red, a wind with no source, the water in Barry’s fish tank rising into the air


“Run, Barry!”

“Good,” Wells murmurs. “Just like that. You go back in time, and you save her, Barry Allen. Undo all the evil I’ve done.”

The faith, the pride – Barry feels something inside of him snap. It’s a lie, it’s all a lie, and Thawne has no right to act like it’s ever been anything else –

“Don’t talk like that,” Barry shouts.

“Like what?” Damn the man, he still sounds calm –

“Like we’re partners,” Barry spits. “Like you’re – ”

“Rooting for you?” Wells pauses. “Proud of you?”

“Like you care.”

“Oh, Barry. I’m hurt.” Thawne (always Thawne, only Thawne) doesn’t sound it. “Fortunately for me, I know the truth.”

“What truth?” Barry’s already shaking his head, though Eobard can’t see him; denial, instinctive and automatic.

“I’ve seen your future. This – all of this – your mother’s life, your father’s freedom – it won’t matter. You will never truly be happy.”

Barry flinches back. Covers it as a deliberate step, though Thawne can’t see – uses the momentum to get into position on the starting line. Says, “I hate you.”

Barry blanks his mind when he says it. Turns off the little mental image of Wells that his imagination’s been helpfully generating this entire time. Barry doesn’t want to be looking at the other man when he says this. Can’t, somehow, even now – even knowing the truth – murderer, mentor – can’t watch, even in his imagination, the barb hit home, the light die out of piercing blue eyes.

Wells says nothing.

“I will always hate you,” Barry insists, driven to it by his enemy’s silence. By the weight of that presence in the speed force, watching, waiting, hating, proud –

Then the presence vanishes, and suddenly time is moving at its normal speed again.

“The accelerator’s structural integrity is holding,” Caitlin is saying.

“We’re ready to inject the particle,” Stein agrees.

“Take your mark,” Cisco calls.

Barry wastes a precious moment, staring dumbly at the intercom’s speaker as if it’s his friends’ faces.

For them, no time has passed. Barry’s entire conversation with Eobard had taken place at the speed of thought.

Focus, Barry, Eobard’s voice whispers in Barry’s memory.

Barry stares down at the masking-tape X on the ground. Slowly – for him – he takes up a runner’s crouch.

The wind kicks up. Speaking over it: Caitlin, awed. “It’s opening,” she breathes.

The pressure drops. Barry feels it first as a thickness in his ears. Then as a prickling on his skin. Then, finally, in the pit of his belly. A tug, pulling him forward. Towards the heart of the collider.

Barry waits. Balance is another gift that the particle accelerator has given him. He’s light on his feet, fluid – it’s the only way to keep his footing when running at super speed. If he weren’t also super nimble, he’d fall.

So he waits, balanced in his runner’s stance. Balanced between the halt and the hurdle. The here and the there. The present and the past.

And the future?

“Now!” Cisco cries.

Time slows around Barry. He draws speed to himself. A chip of paint hangs in midair, halfway from the wall to the ground. The last syllable of Cisco’s cry still lingers in Barry’s ear.

In the suspension of the speed force, ordinary speech isn’t possible. Only a speedster can vibrate their vocal chords fast enough to form phonemes, and only another speedster can process the sounds rapidly enough to reassemble them into words.

Barry doesn’t speak. Therefore it must be Eobard who says the words he hears. The words that slice through Cisco’s last cry and Barry’s few shaky defenses to become the impetus that gears him forwards into his run, into the particle collider, into his past and his future.

“Run, Barry,” Eobard murmurs. “Run.”

Iris is sitting on the couch. Eight years old. A child.

She looks up when the door opens. She smiles.

“I was waiting for you to bring Barry home,” she says, as if it’s the most natural thing in the world.

(Is Barry okay?)

(Yeah. He just passed Mach Two.)

Think of your mother, Eobard calls to Barry. Don’t get distracted, or you’ll end up who knows where.

Barry runs.

“What happened out there today?” Dr. Wells asks. Earnest. Helpful. No hint of Thawne. “You were moving pretty well, and then something caused you to lose focus.”

“I started remembering something,” Barry says. Trusting. No hint of suspicion. “When I was 11, my mother was murdered – ”

Flattering, Eobard says drily, but not exactly the memory I meant. Farther back, Barry, farther back –

(It’s working. It’s working!)

(Inject the hydrogen particle now – )

The world, already rushing by at the edge of Barry’s vision, begins to blur past the point of recognition. The light leeches from the air.

It’s getting dark, Barry says to the only person who can hear him.

“I’ll keep the light on for you,” Nora Allen says.

It’ll get darker before it gets lighter, Eobard says.

“If I turn this light off now, would you be scared?” Nora asks.

Are you scared? Eobard asks.

“No,” Barry replies.

Yes, Barry says. He forgets, somehow, to lie.

“That’s because I’m here with you.”

Me too, Eobard whispers.

“See, you’re not afraid of the dark, Barry.”

But if you keep running –

“You’re afraid of being alone in the dark. And that goes away when you realize something.”

– if you stay focused –

“You’re never really alone.”

– you’ll find your way back to the light.

“You can turn off the light,” the child Barry says.

The particle appears in Barry’s view. A single, bright, shining focal point of light.

Barry Allen never falters.


(What’s that? What happened?)

(Barry – he’s gone!)


(The wormhole – )

(It’s stable.)

(Start the clock.)

Run, Barry –

Darkness. Streaks of red and yellow light. The wind rushing in his ears. Screams.

Mom! Mom!

Barry! Run!

Nora! Hold on!

Barry’s panting. No, he’s gasping – heaving breaths into lungs that have suddenly become too small. He presses himself against the wall of his childhood house. He struggles for breath; he struggles for clarity.

One minute and fifty-two seconds.

He can’t let himself be seen by his childhood self. He has to wait. Wait until his future self grabs his child self, to take him away, to take him to safety. In that moment, he will be the only Barry Allen in this house. In that moment, in Barry’s timeline, the Reverse Flash kills Nora. In that moment is Barry’s opportunity.

Stop Thawne. Save Nora.

Both future speedsters will vanish, undone by the changes in the timestream. Overwritten by the people that their current versions will grow into. Barry will return to his time and continue to be the Flash. Will be the Flash in 2024. And he’ll never need to come back in time. Because the Reverse Flash who had tried to kill him, who had tried to kill Nora – he will also be deleted. Replaced with the version of Eobard Thawne who is even now making his own way back to his correct time of origin.

No fight. No attempted murder of Barry. No murder of Nora. Just two speedsters, born a century and a half apart, who will never meet.

Mom! Barry’s younger self is screaming.

Nora! Nora! Barry’s father cries.

One minute and twenty-four seconds.

There’s a sudden blur, the crackle of lightning. Barry tenses. Is that his other two selves leaving?

He risks the look. He’ll only get one shot at this. He can’t afford to miss it.

It’s not his moment yet. His younger self and father are both in the room now, but there’s no danger of them spotting Barry; all of their attention is focused away from him. Nora is trapped in the eye of the hurricane, yelling at Barry to run, at Henry to take Barry out of there. Both of the Allen men are frozen. Staring, wild-eyed, at the two streaks of light chasing each other angrily about the room.

The two streaks are moving fast, faster than Barry has ever moved. He barely has enough of the speed force to watch them as something other than a set of blurs. Barry sees his future self takes a punch; then, a heartbeat later, the future Flash is on his feet and pressing his advantage, forcing the future Reverse into a corner. But another heartbeat later both combatants have fallen apart, circling at super speed, watching for weaknesses.

Fifty-eight seconds.

Henry’s finally torn his gaze away from the fight and is trying to remove his Barry from the room.

“No!” the young Barry is shouting. “No, no, no – ”

The Reverse Flash’s gaze shifts to the child Barry.

Barry tenses. Here it comes, here it comes –

Something appears in his vision.

The Reverse Flash is wholly occupied with the sight of the child Barry, his goal, the embryonic form of his enemy. His occupation lasts only a moment. But to a speedster, a moment is long enough to take advantage of.

The Flash from the future turns his head unerringly and looks straight at Barry. The future Flash, who – according to everything Barry understands about the timeline – should have no idea that there is a third Flash in the room.

But he looks right at Barry. And he shakes his head.

Barry rears back, too shocked to forget to keep his speed under control, and ends up back tucked in his corner. Not a moment too soon. A split second later there’s a streak of golden light, as his future self takes his past self out of the line of fire. And leaves the Reverse Flash alone with Barry’s mother. With all of their mothers.

This is it. This is Barry’s moment.

Forty-three seconds.

Barry can’t see what’s going on in the room, but he can imagine it, put it together from the recounting Eobard had given him – his Eobard, the one who had posed as Wells. The Reverse Flash has dropped out of super-speed. He’s picking up the knife. He’s taking the two steps necessary to bring him looming over Nora Allen. He’s crouching down next to her and driving the knife into her heart.

It will take perhaps five seconds.

To a speedster, five seconds is an eternity.

Barry has time. All the time he needs. All the time to scream, to run, to chase, to intervene. All the time to wonder why.

Why had his future self told him not to interfere?

How had his future self even known a third Barry is here?

What does his future self know that Barry doesn’t?

Forty-two seconds.

Barry trembles. Not with the speed force, but with the sheer intensity of his longing to fling himself around this wall. Snatch the knife from the Reverse Flash’s hands and bury it in Eobard’s lying, murdering chest. Then yank it out again and use it on his future self. That future self who has never had to live without a mother, who dares to stand in the face of everything Barry has done to get to this point – has fought for and sacrificed for and risked for – to stand in the center of that and say no, don’t, give up, go home, let Nora die –

But how can Barry overlook the possibility that there is something his future self knows that he, Barry, doesn’t? If just getting here risked destroying the entire planet – what consequences might there be to meddling further?

Forty-one seconds.

I already risked everything for this moment. I’ve already agreed to delete the last fifteen years of everyone’s life. What else do I have left to wager? What else do I have to lose?

And again: What does my future self know that I don’t?

Forty seconds.

What do I do?

(Are you scared? Eobard asks. His voice is a memory from the past – from the future – from nowhere and no when at all.)

“Yes,” Barry whispers from his hiding place, voice breaking.

(Me too.)

(But if you keep running – if you stay focused – you’ll find your way back to the light.)

Thirty-nine seconds.

The light.

And suddenly Barry knows what he has to do.

Thirty-eight seconds.

Nora Allen cries out as the knife slides between her ribs.

A red streak of light rushes past Barry and out the front door.

Barry Allen goes in and says his goodbyes to his mother.

Then he starts running.

Thirty seconds.

Will it be long enough?

Barry doesn’t know. He has to try.

Nora is dead. The Barry from the future – the Flash from the future – is gone. If Barry wants answers, he’s going to have to get them from a different source.

Fortunately, he knows exactly where – or, rather, when – his answers may be found.

April 25, 2024.

Barry has thirty seconds. Thirty seconds in which to repeat his run, break the space-time barrier, and reach the future. Reach his future self, moments before coming back in time, and ask him why.

What Barry will do after that, he isn’t prepared to say. But if his future self is fast enough to travel twenty-four years backwards through time without the help of a particle accelerator, Barry’s willing to bet something can be worked out.

Twenty-nine seconds.

A young boy is crying in the street, ten blocks away. Inside an ordinary suburban home, a well-respected local doctor is trying – and failing – to save his wife’s life. Across town, Harrison Wells and Tess Morgan are about to lose their lives in a car accident that will be no accident.

Barry shuts out all those concerns. He runs. He runs, and he focuses.

There’s an image in his mind. It’s not his mother on the floor, shouting. It’s not his younger self being hustled out of the room. It’s not his father, shocked and bloody. It’s not even the man in yellow, who had haunted Barry’s dreams for so long.

It’s Barry’s future self. The Flash from the future. His gaze turned towards Barry. And his head shaking, saying: no.

Barry holds that image in his head as the streets move by more quickly. As the blurs at the edge of his vision begin to darken again. As he feels the fabric of time and space beginning to stretch and warp around him.

As the speed force takes Barry in, Barry holds that image in his mind and poses a single question.


Then the speed force swallows Barry up, carrying him forward to his answers.

Light sears Barry’s eyes. He blinks rapidly – rapidly as only he can – forcing his pupils to adjust, and his vision to focus. The source of the light is revealed to be a massive light fixture in the ceiling. A massive, familiar light fixture.

“Oh my God,” Barry blurts out. “Oh my God, oh my – where am I?”

“He’s up!” Cisco cries.

Barry shoves himself to a sitting position. No. No, it’s can’t be. He can’t have done all of that for nothing! He wanted to go the future, not back to his own time, empty-handed, with Thawne having gotten everything he wanted and vanished beyond Barry’s reach.

But Barry is unmistakably in STAR labs. This is the cortex. This is the medical bay. This is Caitlin shining a light worriedly into his eyes, saying, “Pulse 120, pupils equally reactive to light.”

“No!” Barry shouts in frustration. He tries to bat Caitlin away, tries to stand up. Nothing is working quite right. He feels wrong in his own skin, out of control, wobbly-legged as a newborn colt. He wants to throw something. To scream. To run, as if running had ever solved everything.

Barry doesn’t even manage to make it to a sitting position. Still, his desires must be clear, because Cisco is grabbing his arms to hold him down. “Look at me, look at me. Hey, hey, whoa, whoa, relax. Everything's okay, man. You're at STAR Labs.”

“I know I’m at STAR Labs!” Barry cries. He could break Cisco’s hold – at least, usually he could; right now his muscles feel like mush – but what would be the point? Where would he go? What would he do?

“You… do?” Cisco asks. He exchanges a confused look with Caitlin.

“Did anything change?” Barry asks pleadingly. “Did it make any difference, any difference at all? Damn it, Cisco, tell me I accomplished something more than letting my mother’s murderer go free!”

“Oookay,” Cisco says slowly. “I’m going to need you to tell me how you know my name.”

“How I know your name?” Barry stares at Cisco. “Are you kidding me? That’s what I accomplished? My mom’s dead, she’s still dead, and all I managed to do was erase one of the few friendships I have. That’s great. That’s really fucking great.”

“We’re not friends,” Cisco says even more slowly. He pauses. “Well. I mean, we could be. Maybe. You seem like a nice guy. But we’ve never, you know. Met.”

“At least not while you’re conscious,” Caitlin supplies.

“Shoot me now,” Barry says, heartfelt.

“That would go against my code of medical ethics,” Caitlin says apologetically.

“Do you know me?” Barry asks her. He thinks he’s keeping the hopeful tone out of his voice, but by the way she looks even more sympathetic when she shakes her head, he’s clearly not managed it.

“I’ve been taking care of you for the last nine months, but other than that – ”

“Wait. Nine months?” Barry stares at her, then at Cisco, then at Caitlin again. The length of time sparks an ugly suspicion in his mind. “Nine months. Have I been – have I been in a coma for nine months?”

“Yes! Well, sort of,” Caitlin amends when Cisco gives her a look. “It’s complicated, but, well, effectively, yes.”

“But I wasn’t sick,” Barry says. Slowly. Feeling out the theory that’s taking disturbingly probable form in the back of his mind.

Speed. It all comes down to speed. Barry’s collision with the hydrogen particle had resulted in the release of a huge burst of energy. Some of it had been captured by the particle accelerator’s capacitors, where it was to have been used to power the time-ship and take Thawne back to his time. The rest had been absorbed by Barry himself. That energy had been what had boosted Barry’s speed enough to travel back in time, when ordinarily he couldn’t muster up the speed to travel back nearly so far.

The plan had always been for Barry to expend the energy in two stages. One to return to 2000, and one to return back to the present. That is, to 2015. When Barry had changed his mind and decided to go to the future, to find his answers – he hadn’t thought about his power consumption. He’d just assumed that he had enough energy, not just to return to his own time, but to overshoot it, traveling to 2024.

But if he hadn’t –

“No,” Cisco says. “It’s – well – you were – ”

“I was struck by lightning,” Barry says numbly.

“Yes! You were!” Caitlin looks excited. “You remember that? What was it like?”

“Not the time,” Cisco murmurs.

“Right! Sorry.” Caitlin pauses for a moment. Then, as if she can’t help herself, she rushes on. “It’s just that you were in a coma for nine months, and that’s really unusual, and then there’s all the other stuff that started happening to you – ”

“Stuff that you’re not supposed to bring up immediately because he just got out of a coma,” Cisco says in what he clearly believes to be a loud whisper.

“ – but if you could remember anything – ” Caitlin continues.

“Dr. Snow,” an all-too-familiar voice interrupts. “I believe we had a conversation about overwhelming the patient when he regained consciousness.”

Caitlin looks abashed. “Yes. Sorry, Dr. Wells.”

“But I’m glad to know he’s awake.” The familiar whine of an electric wheelchair meets Barry’s ears. It’s silent to everyone else, but Barry is listening for it, processing the near-immeasurable vibration of the fine bones of his inner ear at a speed that makes the whine audible.

That sound gives Barry the half-second of warning he needs not to react when Dr. Harrison Wells appears, wheelchair and all, at the entrance to the cortex.

“Welcome back, Mr. Allen,” he says. “We have a lot to discuss.”